Method For Injecting Surface Water Into The Ground

ABSTRACT

A method and pumping/drainage channel member for injecting surface water into the soil beneath a ground area includes drilling a series of holes and inserting an elongated pumping/drainage members into each hole extending downwardly into the soil. The pumping/drainage channel members comprise a cluster of integrally joined channel features each formed with a lengthwise extending slot opening. Surface water flows to the pumping/drainage member, enters the channels and drains down the pumping/drainage members to enhance water movement down into the soil to reduce runoff and help to recharge acquifers. Longer members may be installed between shorter members in a pattern to achieve more rapid injection of water deep into the subsoil.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. Ser. No. 12/757,115filed on Apr. 9, 2010 which is a continuation-in-part of U.S.application Ser. No. 11/980,304 filed on Oct. 30, 2007 and also claimsthe benefit of U.S. provisional application No. 61/212,893 filed on Apr.16, 2009.

BACKGROUND OF THE INVENTION

This invention concerns injection of surface water into the subsoil.Rainwater typically partially percolates into the soil but a greaterportion runs off and evaporates to an extent which depends on the slopeof the land. The runoff can create flooding in low lying areas. Standingsurface water can result where the rate of percolation is insufficientand can be a problem particularly if collecting around buildings whereit can enter basement spaces.

Grading is commonly used to direct surface water away from the building.Drain titles are usually laid around the foundation footings to preventwater from collecting around the foundation by draining it away throughthe tiles.

These measures are sometimes ineffective primarily due to particularsoil conditions, the topography of the land, etc.

The water which runs off and/or evaporates could be used to mitigatedrought condition if captured and retained by the subsoil as it wouldmigrate to the upper levels of the soil when dry conditions prevailtending to mitigate drought. Greater recharging of aquifers could resultif greater absorption could be achieved of runoff by faster rates ofwater percolation into the soil.

French drains and drywalls are sometimes used to dry limited areas withporous soil, but this approach is inadequate for larger areas and withheavy soils.

It is the object of the present invention to inject surface water intothe subsoil to eliminate wet conditions produced by standing surfacewater or flooding due to runoff, thereby reducing run off andevaporation of surface water by accelerating the rate of waterabsorption into the subsoil.

SUMMARY OF THE INVENTION

The above object and other objects which will become apparent upon areading of the following specification and claims are achieved bydrilling a pattern of holes into the ground and installing speciallyconfigured elongated pumping/drainage channel members into holes drilledinto the soil, each hole receiving a pumping/drainage channel member.The pumping/drainage channel members are sufficiently rigid to beinserted into the drilled holes in the ground. The pumping/drainagechannel members promote movement of water down into the subsoil bylengthwise channel features which are open to the outside throughlengthwise slots to allow water in the soil to enter into the channelfeatures and flow downwardly. The pumping/drainage channel members aremaintained clear of soil as the ground expands and contracts bydeflection of flexible portions defining the channel features to blockentrance of soil and by water flowing down the channels flushing out thechannels.

The pumping/drainage channel members may be arranged in clusters formedby a repeating pattern of three members with two shorter membersarranged on either side of a longer member. The shorter members are longenough to reach a level preferably four feet below the ground from acapped top end located a short distance below grade to allow some waterfiltration by the over layer of soil before entering the channels. Theshorter members promote water absorption into the upper levels of thesoil. The intermediate longer length pumping/drainage channel membershave a capped top end which may be located at the approximate level ofthe bottom ends of the shorter members to receive water in the soilcollecting around the bottom end of the shorter members by movement downthe channels.

The longer channel members extend down to a significantly deeper level,i.e. to 10-14 or more feet with sloping grades.

As noted, the channel features are open to the outside by lengthwiseslots allowing water to enter the channels all along the length of thechannel members and which rapidly drains down through the channels to alower subsoil level to enhance absorption of water into the subsoil.This dries the soil in a depression cone pattern around thepumping/drainage members to quickly absorb standing water at the surfaceof the soil.

The moisture absorbed in the upper layer of the soil drains into theupper region of the longer members and fills up the lengthwise channelfeatures. The resulting water columns in the channels create increasedwater pressure at the bottom of the channels injecting water into thesoil at the bottom end. In addition, as the surrounding soil becomeswetted, it expands and compresses the channel defining curved wallportions of the members, which are deflected inwardly since made of adurable deflectable plastic, creating additional pressure tending toforce the water in the upper part therein down and to be injected outfrom the lower part of the longer pumping/drainage channel members andinto the subsoil.

As water exits the lower regions of the channels, a vacuum develops inthe upper section of the members which tends to draw in water from thesurrounding soil in the upper regions of the longer members whichspeedily drains down to the lower regions of the members and is injectedinto the surrounding soil.

This water movement also keeps the channels free from soil and debris,to provide a self cleaning action eliminating any maintenance burden.

Thus, surface water is rapidly injected deep into the ground at thelower ends of the channel members.

The inwardly curving portions of the pumping/drainage channel membersdefining the channels are deflectable inwardly in response to increasedsoil moisture and will expand outwardly as the soil dries out tominimize silting up of the channel features.

When the soil dries out during dry conditions, moisture vapor rises upthe channels and disseminates out into the soil surrounding the upperends of the members to provide moisture transmission from the subsoil tothe surface soil but does not form any surface puddles or standingwater.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view through a soil region in which an array ofpump/drainage channel members have been installed in predrilled holes.

FIG. 2 is a diagram of a pattern of pumping/drainage channel membersinstalled adjacent to a paved area.

FIG. 3 is a diagram of the moisture flow patterns around and downpumping/drainage channel members according to the invention installed inwet soil conditions.

FIG. 4 is an enlarged sectional view of a pumping/drainage channelmember in which water is collected in the channel features.

FIG. 5 is a diagram of moisture vapor flow patterns around and up apumping/drainage member installed in dry soil.

FIG. 6 is an enlarged sectional view of a pumping/drainage channelmember depicting the flow of water vapor out therefrom.

FIG. 7 is a sectional diagram of a varying slope ground in whichclusters of pumping/drainage members are installed to of increasinglength and depths as the ground slope increases.

FIG. 8 is a pictorial view of a drilling rig for simultaneous drillingof successive three hole cluster patterns for installation of thepumping/drainage channel members according to the invention.

FIG. 9 is a diagrammatic plan view of successive three-member clusterinstallations.

FIGS. 10-12 are enlarged sectional views of a pumping/drainage channelmember installed in a ground hole with varying degrees of compression byvarying degrees of moisture levels in the surrounding soil.

FIG. 13 is a fragmentary side elevational view of a preferred drillconfiguration for use in drilling holes to receive the pumping/drainagechannel members

DETAILED DESCRIPTION

In the following detailed description, certain specific terminology willbe employed for the sake of clarity and a particular embodimentdescribed in accordance with the requirements of 35 USC 112, but it isto be understood that the same is not intended to be limiting and shouldnot be so construed inasmuch as the invention is capable of taking manyforms and variations within the scope of the appended claims.

Referring to FIGS. 1 and 2, a ground area 10 has been prepared so as tospeed the rate water movement down into the soil according to the methodof the present invention. This preparation comprises installing an arrayof elongated pumping/drainage members 12A, 12B into predrilled holesdispersed over the ground area 10. Preferably, these pumping/drainagechannel members 12A, 12B are arranged in a pattern, with rows of shortermembers 12A on either side of an intermediate row of longerpumping/drainage channel members 12B. This pattern can be repeatedlaterally as necessary.

The members 12A, 12B are located in the vadose zone well above the levelof the water table 15, as the surface water should be completelypurified by passing through a sufficient depth of soil prior to reachingthe water table level to avoid contamination of the ground water.

The spacing of the members 12A,12B depends on the soil drainagecharacteristics, i.e., further apart for more open soils, closertogether for denser soils such that conical zones 14 having a desiredrate of percolation are tangent to each other as seen in FIG. 9.

The pumping/drainage channel members 12A, 12B are of similar shape, onlybeing of different length. The pumping/drainage channel members 12A, 12Bare preferably made of a plastic extrusion, a flexible preferablypolyethylene plastic being suitable for the purposes of the invention,as it is resiliently deflectable, chemically inert so as to not degradein the soil, and has a smooth finish to resist capture of debris.

Each pumping/drainage channel member 12A, 12B as best seen in FIGS. 4and 6 is shaped to have a plurality readily deflectable portions 16extending radially out from an annular center 18 and curving backtowards the center, terminating short of the center to form a lengthwiseslot 20, a plurality of channels 22 thereby formed around the center.

A central hollow 24 is opened by a lengthwise radial slot 26 to allowthe entrance and exit of ground water as the slots 20 do for channels22.

Each of the pumping/drainage members 12A, 12B has a cap 26 at its upperend shown to close off the channels 22, 24 at their upper ends for apurpose to be described below.

The short pumping/drainage channel members 12A, are inserted in theshallow drilled holes at a depth such as to locate their upper end a fewinches below the surface of the soil as shown in FIGS. 3 and 5. The soilover the upper ends filters out any debris in the water draining intothe members 12A.

The members 12A being below grade are not directly exposed to firedamage, but polyethylene can withstand temperatures up to 200° F. andwill not crack at temperatures down to −30° F. so the members are quiteresistant to damage.

The water in the surface layer of soil drains into the shorterpumping/drainage channel members 12A and fills the channels 22 and 24 asindicated in FIG. 3.

The soil which is saturated therefore extends deeper in the groundaround the members 12A. When the ground is saturated with water, theportions 16 are compressed by the soil tending to force the water downthe channels 22, 24, and also avoid silting in of the channels 22, 24 aswill be discussed later.

The water drains down to fill the channels 22, 24 which creates apressure head at the bottom of each channel 22, 24 which creates apressure tending to inject water out from the channels 22, 24 into thesurrounding soil around and beneath the lower end of the shorter members12A, in the cone shaped regions indicated in FIG. 3. This will cause aslight vacuum to develop at the upper end of the member 12A which actsto draw in water out of the surrounding soil and thereby enhance thepercolation rate of water out of the surrounding soil and into thechannel upper regions.

The net effect is a substantially increase in the rate of injection ofwater into the subsoil.

FIG. 4 represents the process of drawing moisture out of the subsoilwhen dry conditions prevail at the surface regions of the soil.

Water vapor passes into the channels 22, 24 and rises to the upperregions of the members 12A and passes out of the channels into thesurrounding soil.

These processes are repeated with the longer pumping/drainage channelmembers 12B, the upper ends receiving the moisture drawn down in theupper members 12A so as to cause injection deep into the ground, asindicated in FIG. 1.

The pattern of pumping/drainage channel members 12A, 12B should bespaced from paved areas as indicated in FIG. 2, a distance on the orderof 7 feet.

FIG. 7 shows application of the method to ground areas having steeplysloping grades. In this application, the longer members 12B arelengthened as the slope increases to insure that surface water quicklyreaches greater depths so as to avoid landslides which could occur ifthe uppermost regions become saturated.

The method quickly drains the upper regions and causes the surface waterto quickly reach sufficiently deep levels so as to avoid landslides fromcomplete saturation of the soil in the surface strata.

Water is thus retained in the soil that would otherwise be lost.Aquifers can be replenished at a greater rate, and flooding problemsmitigated by reducing peak-flow runoff. Most surface water dischargescan be quickly absorbed over large land areas.

The holes are predrilled so as to allow easy insertion therein of thepumping/drainage channel members 12A, 12B.

Advantageously, multiple holes are drilled in clusters to make a uniformpattern easier to achieve. FIG. 8 shows a rig having three hydraulicdrill motors 26A, 26B 26C movably mounted on a frame 28. The frame 28includes two swing arms 30 mounting two of the motors 26A, 26C with thethird motor 26B mounted to a central fixed member 32. The arms 30 can beadjustably swung in and out to set a particular hole spacing necessaryto achieve a desired pattern. A wider spacing hole pattern can bedrilled for porous soils, or holes spaced closer together for lessporous soils.

The frame 28 is vertically movable on an upright support 34 to the depthof the deepest holes to be drilled, i.e., 10 to 16 feet or greater. Thesupport 34 is mounted to a wheeled carriage (not shown) to be quicklypositionable over each successive ground area to be drilled.

The two outer motors 26A, 26C drive relatively short drill bits 36A, 36Ccorresponding to the shorter pumping/drainage channel members 12A whilecentral motor 26B drives a longer drill bit 36B corresponding to thedeepest hole accommodating the long channel member 12B.

The drill bits 36A, 36B preferably form holes by moving the soilradially and to be packed rather than by removing soil to the surface asper a conventional auger. This prevents cave in of the holes

A solid steel rod having a spiral flange welded thereto pitched to forcesoil radially outward; a drill tip threaded to the free end of the rod36A, 36B having radially separated tips formed with adjacent radiallyextending surfaces which push the soil outwardly to be packed against ahole sidewall in forming a hole in soil.

The holes so drilled have much greater stability against cave in,allowing the members 12A, 12B to be readily inserted therein.

The pumping/drainage channel members 12A, 12B are preferably made asplastic extrusions. The shape shown can be produced with careful coolingof the shape exiting the extruder such as to stabilize the shape afterexiting the die.

The walls are stiff but resiliently deflectable under pressure asdescribed above.

FIGS. 10-12 show the deflections undergone when the surrounding soilsbecomes progressively more moist.

In FIG. 10, the member is fit into the hole 50 which approximately, oneand one half inches in diameter to accommodate the members.

In FIG. 11 the hole 50 has become smaller as the soil has absorbedmoisture and the curved wall portions 16, 18 are further deflectedinwardly.

In FIG. 12, the wall portions 16, 18 are further deflected inwardly.

This tends to keep soil from silting up in the channels 22, 24.

As the soil dries out the curved wall portions expand back out.

Thus, the rate of absorption of surface water deep into the soil isgreatly accelerated by the injection process described to preventstanding water or saturation of the top soil layers, reducing loss ofwater by runoff and evaporation, achieving the benefits described above.

1. A drill bit for boring holes in soil comprised of: a method ofdrilling holes in soil which remain open by forcing soil outwardcomprising advancing while rotating a drill rod having at least tworadially spaced tips on a lower end of a said drill rod into the soil,to force soil radially out with radially extending inclined surfaces onsaid spaced tip so as to compact said soil against the radiallysurrounding soil, whereby a soil hole so formed remains open afterwithdrawal of the drill bit.
 2. The method according to claim 1 furtherincluding mounting a spiral drill rod above said tips on to said rodinclined so as to force soil outwardly therefrom to compact soil aroundsaid hole in regions above said tips.
 3. An elongated drainage membercomprised of an elongate plastic member formed with a cluster ofintegrally joined lengthwise extending channel features, each channelfeature having a lengthwise extending slot opening to the outside; acentral, generally tubular portion also having a lengthwise extendingslot opening out to a space between two of said channel features, saidcentral portion surrounded by said cluster of channel features.
 4. Adrill rig for simultaneously drilling sets of three holes in the ground,comprising: a frame mounted for vertical movement on an upright support;three drill motors mounted on said frame which are each adopted toreceive a drill bit projecting downwardly and rotated to simultaneouslythereby drill three spaced apart holes in the ground beneath said frame.5. The drill rig according to claim 4 wherein two of said drill motorsare mounted on a respective swing arm on either side of a central oneother of said drill motors located on said frame between said two drillmotors to enable swinging motion of said two drill motors towards andaway from said central drill motor to enable variable spacing of threeholes drilled in the ground.
 6. The drill rig according to claim 4wherein said frame is advanceable on said upright support of a distanceof 10 to 16 feet thereon and said drill bits are of a correspondinglength to enable drilling holes of said depth of 10 to 16 feet.